German published and examined patent application DE-AS No. 14 29 066 discloses a connector having a component in the form of an attenuator valve of this kind for pressure-gas conduits.
This connector includes in the form of a combination the sealing body of the sealing valve needed for the high-pressure line and a safety valve mechanically connected to the latter. The safety valve opens slowly after the sealing body has been activated so that no pressure impact from the pressure-gas conduit can load sensitive equipment connected in series with the conduit. The sealing body can be opened, for example, with the aid of a rod from the outside. The attenuator valve of this invention can be inserted at any desirable location in the pressure-gas conduit between the sealing valve and the source of pressure gas.
The German patent application referred to above discloses a connector for gas-supply conduits which includes two coaxial valve seats inside a housing. The valve seats coact with respective movable sealing bodies to define respective valves. The first one of the valves is a sealing valve and the second one of the valves is a safety valve mounted in the direction of flow ahead of the first valve. Both valves close with the flow under the force of a spring. The valve body for the sealing valve includes a stepped shaft. The sealing body for the safety valve is mounted so as to be movable along the first step of this shaft which extends to the valve body. The play between the sealing body and the shaft defines a calibrated gas outlet. A spacer spring is mounted between the valve body and the sealing body and is configured so as to attempt to increase the distance between the two bodies. Two springs are mounted one inside the other about the end of the shaft and are each braced on the housing with one end toward the shaft end. With the other end, the outer spring slides with a spring plate over a second step of the shaft and supports itself either on the sealing body or on the end of the first step of the shaft in dependence upon the position of the valve body and its shaft. The inner spring is braced at the end of the second step of the shaft and closes the valve body.
In order to release the flow of gas, a rod is actuated from the outside. The rod is located in an insertable release valve or other device and opens the valve body against the inner spring and, at the same time, lifts the outer spring from the sealing body by means of the shaft with the first step of the latter. However, this sealing body remains on its valve seat under the continuing present pressure difference which continues to be present until this pressure difference is balanced by means of the calibrated play between the sealing body and the shaft. Thereafter, the sealing body lifts under the action of the spacer spring and slowly opens the through passage.